Ultrasonic Scaler Research Articles

Antimicrobial efficiency and cytocompatibility of different decontamination methods on titanium and zirconium surfaces.

The purpose of this study was to investigate the efficiency of different implant-decontamination methods regarding biofilm modification and potential cytotoxic effects. Therefore, the amount of biofilm reduction, cytocompatibility, and elementary surface alterations were evaluated after decontamination of titanium and zirconium surfaces. Titanium and zirconium disks were contaminated with a newly developed high-adherence biofilm consisting of six microbial species. Decontaminations were performed using titanium curette, stainless steel ultrasonic scaler (US), glycine (GPAP) and erythritol (EPAP) powder air-polishing, Er:YAG laser, 1% chlorhexidine (CHX), 10% povidone-iodine (PVI), 14% doxycycline (doxy), and 0.95% NaOCl solution. Microbiologic analysis was done using real-time qPCR. For assessment of cytocompatibility, a multiplex assay for the detection of cytotoxicity, viability, and apoptosis on human gingival fibroblasts was performed. X-ray photoelectron spectroscopy (XPS) was used to evaluate chemical alterations on implant surfaces. Compared with untreated control disks, only GPAP, EPAP, US, and Er:YAG laser significantly reduced rRNA counts (activity) on titanium and zirconium (p< .01), whereas NaOCl decreased rRNA count on titanium (p< .01). Genome count (bacterial presence) was significantly reduced by GPAP, EPAP, and US on zirconium only (p< .05). X-ray photoelectron spectroscopy analyses revealed relevant re-exposure of implant surface elements after GPAP, EPAP, and US treatment on both materials, however, not after Er:YAG laser application. Cytocompatibility was impaired by CHX, PVI, doxy, and NaOCl. CHX and PVI resulted in the lowest viability and doxy in the highest apoptosis. Within the limits of this in vitro study, air-polishing methods and ultrasonic device resulted in effective biofilm inactivation with surface re-exposure and favorable cytocompatibility on titanium and zirconium. Chemical agents, when applied on implant surfaces, may cause potential cytotoxic effects.

Role of supportive periodontal management in patient with metastatic cancer

Background: Treatment of head and neck cancers may cause sequelae affecting patients’ quality of life during and after treatment. As a result, periodontal management of a patient with parotid gland adenoid cystic carcinoma, particularly in advanced stage 4, can be challenging for dental practitioners, especially if the patient is on active oral molecular therapy and undergoing long-term radiotherapy and chemotherapy. Purpose: This report was intended to describe the conservative non-surgical management of tooth 27 with poor prognosis owing to grade II mobility in a patient on active Lenvatinib therapy – where the extraction was not advisable to lessen the risk of osteonecrosis. Case: A 52-year-old female patient was referred by an oncologist to our dental clinic for noncarious toothache. Five years ago, the patient was diagnosed with adenoid cystic carcinoma (ACC) and had a treatment history of radiotherapy, chemotherapy and surgical removal of the left parotid gland to manage the malignancy. Oral examination revealed characteristic findings of periodontitis. Case Management: Ultrasonic scaling, antimicrobial mouth rinses and reinforcement in oral hygiene instructions manage the tooth 27 conservatively. Conclusion: A cautious approach by the dental surgeon, together with the multidisciplinary team caring for cancer patients, is fundamental and helps with the palliative periodontal management of this patient to enhance oral health-related quality of life. With a lack of reports on conservative periodontal therapy in ACC patients, this report highlights the combination of smoking cessation, reinforcement of oral hygiene instructions and conservative periodontal treatment.

Aerosol concentrations and size distributions during clinical dental procedures

BackgroundSuspected aerosol-generating dental instruments may cause risks for operators by transmitting pathogens, such as the SARS-CoV-2 virus. The aim of our study was to measure aerosol generation in various dental procedures in clinical settings. MethodsThe study population comprised of 84 patients who underwent 253 different dental procedures measured with Optical Particle Sizer in a dental office setting. Aerosol particles from 0.3 to 10 μm in diameter were measured. Dental procedures included oral examinations (N = 52), restorative procedures with air turbine handpiece (N = 8), high-speed (N = 6) and low-speed (N = 30) handpieces, ultrasonic scaling (N = 31), periodontal treatment using hand instruments (N = 60), endodontic treatment (N = 12), intraoral radiographs (N = 24), and dental local anesthesia (N = 31). ResultsAir turbine handpieces significantly elevated <1 μm particle median (p = 0.013) and maximum (p = 0.016) aerosol number concentrations as well as aerosol particle mass concentrations (p = 0.046 and p = 0.006) compared to the background aerosol levels preceding the operation. Low-speed dental handpieces elevated >5 μm median (p = 0.023), maximum (p = 0.013) particle number concentrations,> 5 μm particle mass concentrations (p = 0.021) and maximum total particle mass concentrations (p = 0.022). High-speed dental handpieces elevated aerosol concentration levels compared to the levels produced during oral examination. ConclusionsAir turbine handpieces produced the highest levels of <1 μm aerosols and total particle number concentrations when compared to the other commonly used instruments. In addition, high- and low-speed dental handpieces and ultrasonic scalers elevated the aerosol concentration levels compared to the aerosol levels measured during oral examination. These aerosol-generating procedures, involving air turbine, high- and low-speed handpiece, and ultrasonic scaler, should be performed with caution. Clinical significanceAerosol generating dental instruments, especially air turbine, should be used with adequate precautions (rubber dam, high-volume evacuation, FFP-respirators), because aerosols can cause a potential risk for operators and substitution of air turbine for high-speed dental handpiece in poor epidemic situations should be considered to reduce the risk of aerosol transmission.

Ultrafine particles exposure is associated with specific operative procedures in a multi-chair dental clinic

Air quality in dental clinics is critical, especially in light of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, given that dental professionals and patients are at risk of regular exposure to aerosols and bioaerosols in dental clinics. High levels of ultrafine particles (UFP) may be produced by dental procedures. This study aimed to quantify ultrafine particles (UFP) concentrations in a real multi-chair dental clinic and compare the levels of UFP produced by different dental procedures. The efficiency of a high-volume evacuator (HVE) in reducing the UFP concentrations during dental procedures was also assessed. UFP concentrations were measured both inside and outside of a dental clinic in Shanghai, China during a 12-day period from July to September 2020. Dental activities were recorded during working hours. The mean (±standard deviation) concentrations of indoor and outdoor UFP during the sampling period were 8,209 (±4,407) counts/cm3 and 15,984 (±7,977) counts/cm3, respectively. The indoor UFP concentration was much higher during working hours (10,057 ± 5,725 counts/cm3) than during non-working hours (7,163 ± 2,972 counts/cm3). The UFP concentrations increased significantly during laser periodontal treatment, root canal filling, tooth drilling, and grinding, and were slightly elevated during ultrasonic scaling or tooth extraction by piezo-surgery. The highest UFP concentration (241,136 counts/cm3) was observed during laser periodontal treatment, followed by root canal filling (75,034 counts/cm3), which showed the second highest level. The use of an HVE resulted in lower number concentration of UFP when drilling and grinding teeth with high-speed handpieces, but did not significantly reduce UFP measured during laser periodontal therapy. we found that many dental procedures can generate high concentration of UFP in dental clinics, which may have a great health impact on the dental workers. The use of an HVE may help reduce the exposure to UFP during the use of high-speed handpieces.

Cavitation in a periodontal pocket by an ultrasonic dental scaler: A numerical investigation

Periodontal pockets are spaces or holes surrounded by teeth under the gum line. These pockets can become filled with infection-causing bacteria resulting in tissue, bone, and tooth loss. Cavitation produced by the oscillating tip of dental ultrasonic scalers plays a significant role in routine periodontal therapy to clean these areas. Numerical studies were conducted for a scaler vibrating in a periodontal pocket which was simplified to a hole, using ABAQUS based on the finite element method. The simulations consider the three-dimensional, nonlinear, and transient interaction between the vibration and deformation of the scaler tip, the water flow around the scaler and the cavitation formation. The numerical model was validated by comparing results with experimental data for a scaler vibrating in an unbounded liquid, the displacement at the free end of the scaler and the cavitation pattern near the scaler tip displaying excellent agreement. A parametric study for a scaler vibrating in a hole has been carried out in terms of the volume of the hole, the taper ratio (the radius ratio between the circular opening and bottom of the hole), and the immersion depth of the scaler tip in the hole. The amount of cavitation generated is evaluated by the cavitation density (or the void fraction) which is the ratio of the volume of the cavitation occupied in the hole to the total volume of the hole. Numerical results indicate that the cavitation density in the hole increases with the decreasing hole volume and the increasing taper ratio. It is inferred that cleaning effects could be increased if some modifications to the scaler design could be made to increase the blocking effect of the hole during the cleaning process. Cavitation is observed in the hole even if the scaler is placed above the hole and increases with the immersion depth.

Bioaerosol distribution characteristics and potential SARS-CoV-2 infection risk in a multi-compartment dental clinic

Dental clinics have a potential risk of infection, particularly during the COVID-19 pandemic. Multi-compartment dental clinics are widely used in general hospitals and independent clinics. This study utilised computational fluid dynamics to investigate the bioaerosol distribution characteristics in a multi-compartment dental clinic through spatiotemporal distribution, working area time-varying concentrations, and key surface deposition. The infection probability of SARS-CoV-2 for the dental staff and patients was calculated using the Wells–Riley model. In addition, the accuracy of the numerical model was verified by field measurements of aerosol concentrations performed during a clinical ultrasonic scaling procedure. The results showed that bioaerosols were mainly distributed in the compartments where the patients were treated. The average infection probability was 3.8% for dental staff. The average deposition number per unit area of the treatment chair and table are 28729 pcs/m2 and 7945 pcs/m2, respectively, which creates a possible contact transmission risk. Moreover, there was a certain cross-infection risk in adjacent compartments, and the average infection probability for patients was 0.84%. The bioaerosol concentrations of the working area in each compartment 30 min post-treatment were reduced to 0.07% of those during treatment, and the infection probability was <0.05%. The results will contribute to an in-depth understanding of the infection risk in multi-compartment dental clinics, forming feasible suggestions for management to efficiently support epidemic prevention and control in dental clinics.

Dental Aerosol Hazard Prevention with Pre-procedural Antiseptic Mouthwashes (Comparative Study)

Background: One of the recommended methods for reducing aerosol contamination during the daily regular usage of high-speed turbine and ultrasonic scaling is the use of preprocedural mouth rinse. Several agents have been investigated as a preprocedural mouth rinse. Chlorhexidine significantly reduce the viable microbial content of aerosol when used as a preprocedural rinse. Studies have shown that cetylpridinum chloride (CPC) mouthwash is equally effective as chlorhexidine in reducing plaque and gingivitis. This study compared the effect of 0.07% CPC to 0.2% chlorhexidine gluconate (CHX) as preprocedural mouth rinses in reducing the aerosol contamination by high-speed turbine. Materials and Methods: 36 patients were divided into three groups based on the preprocedural rinse used (0.2% CHX, 0.07% CPC and distilled water). Conservative treatment was done for 20 min. (10 min before rinsing and 10 min after rinsing) in the same closed operatory for all the patients after keeping blood agar plates opened at three standardized locations (patient chest, dentist chest and at 12-inch from patient mouth). Colony forming units (CFUs) on blood agar plates were counted, after incubation at 37°C for 48 hr. Statistical analysis was done with (SPSS version 21(. Results: This study showed that the two antiseptic mouthwashes significantly reduced the bacterial colony forming units (CFUs) in aerosol samples at three plates locations. Chlorhexidine rinses were found to be superior to cetylpridinum chloride when used pre-procedurally in reducing aerolized bacteria. The number of CFUs were higher at the patient’s chest location as compared to other locations. Conclusion: 0.07% CPC and 0.2% CHX were effective as a pre-procedural rinse in reducing CFU count during dental treatment using high-speed turbine.

Aerosol reduction efficacy of different intra-oral suction devices during ultrasonic scaling and high-speed handpiece use

BackgroundThe COVID-19 pandemic led to significant changes in the provision of dental services, aimed at reducing the spread of respiratory pathogens through restrictions on aerosol generating procedures (AGPs). Evaluating the risk that AGPs pose in terms of SARS-CoV-2 transmission is complex, and measuring dental aerosols is challenging. To date, few studies focus on intra-oral suction. This study sought to assess the effectiveness of commonly used intra-oral suction devices on aerosol mitigation.MethodsUltrasonic scaling and high-speed handpiece procedures were undertaken to generate aerosol particles. Multiple particle sensors were positioned near the oral cavity. Sensor data were extracted using single board computers with custom in-house Bash code. Different high-volume and low-volume suction devices, both static and dynamic, were evaluated for their efficacy in preventing particle escape during procedures.ResultsIn all AGPs the use of any suction device tested resulted in a significant reduction in particle counts compared with no suction. Low-volume and static suction devices showed spikes in particle count demonstrating moments where particles were able to escape from the oral cavity. High-volume dynamic suction devices, however, consistently reduced the particle count to background levels, appearing to eliminate particle escape.ConclusionsDynamic high-volume suction devices that follow the path of the aerosol generating device effectively eliminate aerosol particles escaping from the oral cavity, in contrast to static devices which allow periodic escape of aerosol particles. Measuring the risk of SARS-CoV-2 transmission in a dental setting is multi-factorial; however, these data suggest that the appropriate choice of suction equipment may further reduce the risk from AGPs.

Effects of preprocedural mouth rinse on microbial load in aerosols produced during the ultrasonic scaling: A randomized controlled trial.

During ultrasonic scaling, the harbored microorganisms in the oral cavity get aerosolized, which have important impacts on air quality and can cause a serious health threat to the clinician, patients, and the surroundings. Therefore, this study was conducted to evaluate whether preprocedural mouth rinse has any effect on bacterial load in aerosols generated during ultrasonic scaling. A total of 80 subjects with chronic periodontitis were selected and randomly grouped into four comprising twenty in each. The groups were based on the use of preprocedural mouth rinse: no rinse group (control) (A), and test groups with preprocedural mouth rinse with water (B), 0.2% Chlorhexidine gluconate (C), and herbal mouthwash (D). The aerosol produced during ultrasonic scaling was collected on blood agar plates positioned at the chest area of patients, operators, and assistants. Aerosol collected in the operatory before the procedure was considered as baseline. Colonies on the blood agar plates were counted after incubating at 37°C for 24 h. Pairwise comparisons involving positions and mouth rinses on microbial colonies were conducted using independent sample t-test and Tukey's test for post hoc analysis considering 0.05 as the significance level. Microbial colonies were significantly reduced with chlorhexidine gluconate compared to that of others (P < 0.001), followed by herbal mouthwash and water. Again, microbial colonies were highest at the chest area of the operator and lowest at the chest area of the assistant. 0.2% Chlorhexidine gluconate is superior in reducing the microbial load in aerosols produced during ultrasonic scaling.

The Effect of Dental Ultrasonic Scaler on Dental Restorations

The ultrasonic scalers are today becoming the most chosen form of dental polishing and cleaning. With the various researchers and lab tests done on them, it is steered clear of any side effects or invasive methodologies that might harm the patient in any manner. It works both on the soft and hard oral tissues have become the most widely used cleaning instruments among dental practitioners. Ultrasonic scalers use its vibrating power to eradicate different forms of dental plague and foreign components from the teeth. Through various on-field experiments and lab tests, it was made sure that these ultrasonic scalers work much better than any other primitive method for the same task. And that’s the major reason why it is so much in demand, ultrasonic scaling has become widely used for professional tooth cleaning. The aim of the systematic review is to assess the role of ultrasonic scaling on dental restoration. A computerized literature search was performed in following database including: Pubmed, the Cochrane Library, Google Scholar and Scopus databases from 1st January 2000 till January 2022. Studies determining the impact of ultrasonic scaling on dental restorations including randomized controlled trials, prospective and retrospective studies, and cross-sectional studies were included. After an initial search a total of 570 articles were identified. Then, 44 studies which were full-text articles were critically reviewed by independently for eligibility. Finally, 10 studies which met all the inclusion criteria were included in the review. The findings showed that out of all of the elements used, we can observe that the glass ionomers have had the chances of greater impacts. Further studies should assess the method of polishing for the removal of discolorations from ceramic restorations after ultrasonic scaling procedures and the possible side effects of polishing.

Efficacy of Er:YAG laser for the peri-implantitis treatment and microbiological changes: a randomized controlled trial.

The aims of this study were to identify the microbiological changes in the periodontal pockets following an Er:YAG laser (ERL) irradiation and mechanical debridement to compare the effectiveness of ERL irradiation to mechanical debridement for peri-implantitis treatment through randomized controlled trials. Twenty-three patients with peri-implantitis lesions were treated in either a test group, ERL set at energy level of 100mJ/pulse, frequency of 10Hz, pulse duration was 100µs, and irradiated by three passages, or a control group, with mechanical debridement using an ultrasonic scaler. An examiner measured the following clinical parameters at different stages (a baseline and at 3- and 6-month post-treatment): probing depth (PD), bleeding on probing (BOP), marginal bone loss (MBL), and anaerobic bacteria counts. Linear regression, with generalized estimation equations, was used to compare the clinical parameters and anaerobic bacterial counts at different stages and between groups. The anaerobic bacterial counts significantly decreased within the control group during the follow-ups. At the 6-month follow-up, both groups showed a significant reduction in PD (test group: mean difference of 0.84mm; control group: mean difference of 0.41mm), and the test group showed a significantly higher PD reduction on the buccal site (1.31mm) compared to that of the control group (0.25mm). Both ERL and mechanical debridement treatments led to significant improvements in PD. When mechanical debridement therapy was used, significant anaerobic bacterial count reductions were observed. Future treatment of peri-implantitis should involve a combination of both of these therapies.

Dental high-speed handpiece and ultrasonic scaler aerosol generation levels and the effect of suction and air supply.

Exposure to aerosol spray generated by high-speed handpieces (HSHs) and ultrasonic scalers poses a significant health risk to oral health practitioners from airborne pathogens. Aerosol generation varies with different HSH designs, but to date, no study has measured this. We measured and compared aerosol generation by (1) dental HSHs with 3 different coolant port designs and (2) ultrasonic scalers with no suction, low-volume evacuation (LVE) or high-volume evacuation (HVE). Measurements used a particle counter placed near the operator's face in a single-chair, mechanically ventilated dental surgery. Volume concentrations of aerosol, totaled across a 0.3-25-µm size range, were compared for each test condition. HSH drilling and scaling produced significantly high aerosol levels (P < .001) with total volume concentrations 4.73×108µm3/m3 and 4.18×107µm3/m3, respectively. For scaling, mean volume of aerosol was highest with no suction followed by LVE and HVE (P < .001). We detected a negative correlation with both LVE and HVE, indicating that scaling with suction improved operator safety. For drilling, simulated cavity preparation with a 1-port HSH generated the most aerosol (P < .01), followed by a 4-port HSH. Independent of the number of cooling ports, lack of suction caused higher aerosol volume (1.98×107 µm3/m3) whereas HVE significantly reduced volume to -4.47×105 µm3/m3. High concentrations of dental aerosol found during HSH cavity preparation or ultrasonic scaling present a risk of infection, confirming the advice to use respiratory PPE. HVE and LVE both effectively reduced aerosol generation during scaling, whereas the new aerosol-reducing 'no air' function was highly effective and can be recommended for HSH drilling.

Comparative Dissemination of Aerosol and Splatter Using Suction Device during Ultrasonic Scaling: A Pilot Study.

Objective: This study compared the aerosol and splatter diameter and count numbers produced by a dental mouth prop with a suction holder device and a saliva ejector during ultrasonic scaling in a clinical setting. Methodology: Fluorescein dye was placed in the dental equipment irrigation reservoirs with a mannequin, and an ultrasonic scaler was employed. The procedures were performed three times per device. The upper and bottom board papers were placed on the laboratory platform. All processes used an ultrasonic scaler to generate aerosol and splatter. A dental mouth prop with a suction holder and a saliva ejector were also tested. Photographic analysis was used to examine the fluorescein samples, followed by image processing in Python and assessment of the diameter and count number. For device comparison, statistics were used with an independent t-test. Result: When using the dental mouth prop with a suction holder, the scaler produced aerosol particles that were maintained on the upper board paper (mean ± SD: 1080 ± 662 µm) compared to on the bottom board paper (1230 ± 1020 µm). When the saliva ejector was used, it was found that the diameter of the aerosol on the upper board paper was 900 ± 580 µm, and the diameter on the bottom board paper was 1000 ± 756 µm. Conclusion: There was a significant difference in the aerosol and splatter particle diameter and count number between the dental mouth prop with a suction holder and saliva ejector (p < 0.05). Furthermore, the results revealed that there was a statistically significant difference between the two groups on the upper and bottom board papers.

Concise evaluation and therapeutic guidelines for severe periodontitis: A public health perspective.

The main goal of periodontology is to prevent and arrest gingivitis and periodontitis to avoid tooth loss and focal infection of periodontal origin. Periodontal scaling or flap surgery of moderate-to-severe periodontitis have shortcomings, most likely because removal of herpesviruses and bacterial pathogens in deep periodontal lesions and the adjacent inflamed gingiva requires systemic antimicrobial treatment (or gingivectomy). Valacyclovir (1000 mg twice daily on day 1, and 500 mg twice daily on day 2 and on day 3) is a potent anti-herpesvirus agent. Antibiotic combinations against bacterial pathogens include amoxicillin-metronidazole (250 mg of each, thrice daily for 4 days; for systemically healthy adults) and ciprofloxacin-metronidazole (500 mg of each, twice daily for 4 days; for immunosuppressed individuals and patients exposed to contaminated water and poor sanitation). Supportive antiseptic treatment may consist of 0.1%-0.2% sodium hypochlorite (regular household bleach) as cooling spray in ultrasonic scalers, flosser fluid in oral irrigators, and mouthrinse in patient self-care. The anti-infective treatment described here helps control cases of severe periodontitis and constitutes an exceedingly inexpensive alternative to conventional (mechanical) periodontal therapy.

Clinical Efficacy and Safety of Antimicrobial Photodynamic Therapy in Residual Periodontal Pockets during the Maintenance Phase.

Antimicrobial photodynamic therapy (a-PDT) in combination with scaling root planing (SRP) is more effective at improving periodontal status than SRP alone. However, the effectiveness of a-PDT in combination with irrigation for patients undergoing periodontal maintenance has not been clarified. This study evaluated the efficacy and safety of a-PDT in the maintenance phase. Patients who had multiple sites with bleeding on probing (BOP) and periodontal probing depth (PPD) of 4–6 mm in the maintenance phase were treated with a split-mouth design. These sites were randomly assigned to one of two groups: the a-PDT group and the irrigation group. In the a-PDT group, the periodontal pockets were treated with light-sensitive toluidine blue and a light irradiator. In the irrigation group, the periodontal pockets were simply irrigated using an ultrasonic scaler. After 7 days, the safety and efficacy of a-PDT were assessed. The mean PPD of the a-PDT group had reduced from 4.50 mm to 4.13 mm, whereas negligible change was observed in the irrigation group. BOP significantly improved from 100% to 33% in the PDT group, whereas it hardly changed in the irrigation group. No adverse events were observed in any patients. a-PDT may be useful as a noninvasive treatment in the maintenance phase, especially in patients with relatively deep periodontal pocket.

Pandemic Preparedness and Response: A Foldable Tent to Safely Remove Contaminated Dental Aerosols—Clinical Study and Patient Experience

The D-DART (Droplet and Aerosol Reducing Tent) is a foldable design that can be attached to the dental chair to prevent the spread of contaminated dental aerosols. The objective of this study was to evaluate the ability of the D-DART to reduce spread of aerosols generated during dental treatment. Thirty-two patients (sixteen per group) undergoing deep ultrasonic scaling were recruited and randomly allocated to groups D-DART or Control (no D-DART). After 20 min from the start of the treatment, the clinician’s face shield and dental chair light were swabbed and the viable microbial load was quantified (ATP bioluminescence analysis, blinded operator). Statistical analyses were performed with Tukey’s Honest Test with a level of significance pre-set at 5%. There were significant increases in ATP values obtained from the operator’s face shield and dental chair light for the Control compared with baseline (31.3 ± 8.5 and fold increase). There was no significant change in microbial load when the D-DART was used compared with baseline (1.5 ± 0.4 fold increase). The D-DART contained and prevented the spread of aerosols generated during deep scaling procedures.

Comparative Evaluation of Surface Roughness of Porcelain Fused to Metal and Stainless-Steel Crown Following Ultrasonic and Hand Scaling: A Comparative Study.

IntroductionSurface roughness encourages plaque retention and causes mechanical, chemical, and biological irritation to surrounding soft tissues. Hence, a smooth surface of restoration is preferred for optimal plaque control and the health of the periodontium.AimThe aim is to evaluate and compare the surface roughness of porcelain fused to metal and stainless-steel crowns following ultrasonic and hand scaling techniques.Material and methodsAn in-vitro study was conducted on 30 porcelain fused to metal crowns and 30 stainless-steel crowns. Their surface roughness following instrumentation was evaluated by scanning electron microscope (SEM) and profilometry.ResultsEvaluation by profilometry indicated that porcelain fused to metal following ultrasonic instrumentation has a statistically more significant surface roughness and indentation as compared to hand scaling with p-values < 0.05.ConclusionThe surface roughness of any restoration may act as a plaque retentive factor which would affect the health of the periodontium. Ultrasonic scaling is capable of creating roughness to a more extent as compared to hand scaling and porcelain fused to the metal type of restorations is more vulnerable to roughness.

A 19-Year Study of Dental Needlestick and Sharps Injuries in Japan

BackgroundNeedlestick and sharps injuries (NSIs) are serious problems for dental health care workers (DHCWs) because they are at risk for occupational blood-borne infections. In this study, risk factors for NSIs in DHCWs at Tohoku University Hospital (TUH) in Japan over 19 years were analysed. MethodsNSI data of DHCWs at TUH from April 2002 to March 2020 were collected from the Exposure Prevention Information Network (EPINet) and statistically analysed. ResultsA total of 195 NSIs occurred during the 19-year study period. Approximately 58.5% of NSIs occurred in DHCWs with less than 5 years of experience. Injection needles were the most frequent cause of NSIs (19.0%) followed by suture needles (13.3%) and ultrasonic scaler chips (12.8%). Needle injuries occurred mainly on the left hand, whereas ultrasonic scaler chip and bur injuries occurred on the right hand and other body parts whilst DHCWs were placing the instruments back on the dental unit hanging holder without removing the sharps. NSIs from other instruments primarily occurred on both hands and foot insteps during cleanup. No case of occupational blood-borne infection caused by NSIs was observed during the study period at TUH. ConclusionsNSIs occurred in DHCWs with less experience, and there were associations between the instruments, timing of use, and NSI site. EPINet was considered a valuable tool for monitoring NSIs in order to develop future strategies for minimising NSIs.

Oral management of poorly understood Papillon–Lefèvre syndrome – A case report

Rationale: Papillon-Lefèvre syndrome (PLS) is a rare genodermatosis with autosomal-recessive genetic inheritanceand has features mainly palmoplantar hyperkeratosis and rapidly progressing severe periodontitis leading to early loss of deciduous and permanent dentition. Patient Concerns: The patient in the presented report was concerned with loose teeth, gingival bleeding and oral malodour and wanted to get missing teeth replaced. Diagnosis: The diagnosis was made based on medical history, clinical and radiological findings. Interventions: Periodontal phase I therapy included extraction of hopeless teeth, manual and ultrasonic scaling, mechanical and chemical plaque control and periodic maintenance. Missing teeth were restored by removable and fixed prosthesis. Dermatological lesions were conservatively managed. Outcomes: A comprehensive treatment stabilised periodontal disease of the patient and prosthetic rehabilitation improved oral health related quality of life of PLS patient. Lessons: PLS patients require an early diagnosis and a team approach for dermatological, periodontal complications and prosthetic rehabilitation.

In Vitro Evaluation of Root Surface Roughness in The Use of an Ultrasonic Device with Different Tips Having Different Mechanism of Action: A Profilometric Study

Objective: The aim of this study was the profilometric evaluation of the changes in root surface roughness created by different types of ultrasonic tips and mechanism of action.&#x0D; Methods: Thirty root dentine samples obtained from 15 maxillary premolars, extracted for orthodontic reasons, were included in the study. The sample surfaces were embedded into acrylic blocks, polished, and divided into 3 study groups as linear oscillating device (LOD) with straight tip (ST); LOD with perio-curette tip (PCT); conventional ultrasonic scaler tip (CUST). A calibrated clinician instrumented all surfaces in each group. The root surfaces were evaluated before and after instrumentations with a profilometer device.&#x0D; Results: There were no statistical differences between the initial roughness values of the groups (p